JP2018520591A - Signal transmission method and apparatus in wireless communication system - Google Patents

Abstract

The present invention relates to a wireless communication system. Specifically, the present invention is based on the steps of receiving system information indicating a TDD UL-DL configuration, receiving MBSFN SF allocation information, and SF # n TTI configuration. If SF # n is a non-MBSFN SF, SF # n is composed of a single TTI, and if SF # n is an MBSFN SF, SF # n is a multi-TTI. The present invention relates to a method and an apparatus therefor. [Selection] FIG.

Description

  The present invention relates to wireless communication systems, and more particularly, to a method and apparatus for transmitting / receiving signals. A wireless communication system can support carrier aggregation (CA).

  Wireless communication systems are widely deployed to provide various types of communication services such as voice and data. Generally, a wireless communication system is a multiple access system that can share available system resources (bandwidth, transmission power, etc.) and support communication with multiple users. Examples of the multiple access system include a code division multiple access (CDMA) system, a frequency division multiple access (FDMA) system, a time division multiple access (TDMA) system, and an orthogonal multiaccess system (OFDMA). a carrier frequency division multiple access) system.

  An object of the present invention is to provide a method and apparatus for efficiently transmitting / receiving a signal in a wireless communication system. Another object of the present invention is to provide a method for efficiently controlling transmission of an uplink signal and an apparatus therefor.

  The technical problem to be achieved by the present invention is not limited to the technical problem described above, and other technical problems not mentioned have general knowledge in the technical field to which the present invention belongs from the following description. It will be clearly understood by the person.

  In one aspect of the present invention, a terminal performs signal processing in a wireless communication system, and receives MBSFN (system information indicating a TDD (Time Division Duplex) UL-DL configuration (Uplink-Downlink configuration). Receiving a Multicast Broadcast Single Frequency Network (SF) allocation information, and performing a signal processing process for the SF #n based on a TTI (Transmission Time Interval) configuration of the SF #n. When SF # n is a non-MBSFN SF, the SF # n is composed of a single TTI, and when the SF # n is an MBSFN SF, the SF # n A method comprising a TTI is provided.

  In another aspect of the present invention, a terminal used in a wireless communication system includes an RF (Radio Frequency) unit and a processor, wherein the processor is a TDD (Time Division Duplex) UL-DL configuration (Uplink-Downlink configuration). ), System information indicating MBSFN (Multicast Broadcast Single Frequency Network) SF (subframe) allocation information, SF # n based on the TTI (Transmission Time Interval) configuration, and the SF # When SF # n is a non-MBSFN SF, the SF # n is configured with a single TTI. When SF # n is MBSFN SF, a terminal configured with multi-TTI is provided for SF # n.

  Preferably, when the SF # n is an MBSFN SF, the SF # n may include one or more DL sections and one or more UL sections corresponding to the multi-TTI.

  Preferably, when the SF # n is an MBSFN SF, the SF # n may include a plurality of DL sections corresponding to the multi-TTI.

  Preferably, when the SF # n is a non-MBSFN SF, the TTI may be composed of 14 OFDMA (Orthogonal Frequency Multiple Access) symbols, and when the SF # n is an MBSFN SF, the TTI is 3 Of OFDMA symbols.

  Preferably, when the SF # n is a non-MBSFN SF, the TTI can be composed of two 0.5 ms slots, and when the SF # n is an MBSFN SF, the TTI is one 0.5 ms slot. Can be configured with.

  According to the present invention, signals can be efficiently transmitted / received in a wireless communication system. Also, uplink signal transmission can be efficiently controlled.

  The effects obtained by the present invention are not limited to the effects mentioned above, and other effects not mentioned are clearly understood by those having ordinary knowledge in the technical field to which the present invention belongs from the following description. Will be done.

  The accompanying drawings, which are included as part of the detailed description to assist in understanding the present invention, provide examples of the present invention and together with the detailed description, explain the technical idea of the present invention.

It is a figure which illustrates the physical channel used for 3GPP LTE system which is an example of a radio | wireless communications system, and the general signal transmission method using the same. FIG. 2 is a diagram illustrating a structure of a radio frame. It is a figure which illustrates the resource grid of a downlink slot. It is a figure which shows the structure of a downlink sub-frame. It is a figure which shows the structure of an uplink sub-frame. It is a figure which shows a TDD UL ACK / NACK (Uplink Acknowledgment / Negative Acknowledgment) transmission timing in the situation of a single cell. It is a figure which shows TDD UL ACK / NACK transmission timing in the situation of a single cell. It is a figure which shows TDD PUSCH (Physical UpShared Shared Channel) transmission timing in the situation of a single cell. It is a figure which shows TDD PUSCH transmission timing in the situation of a single cell. It is a figure which shows a TDD DL ACK / NACK transmission timing in the condition of a single cell. It is a figure which shows a TDD DL ACK / NACK transmission timing in the condition of a single cell. It is a figure which illustrates an uplink-downlink frame timing. It is a figure which illustrates the case where a short DL / UL structure method is applied in a TDD system. FIG. 6 is a diagram illustrating a signal processing process according to an embodiment of the present invention. It is a figure which illustrates the base station and terminal which can be applied to one Example of this invention.

  The following technologies, CDMA (Code Division Multiple Access), FDMA (Frequency Division Multiple Access), TDMA (Time Division Multiple Access), OFDMA (Orthogonal Frequency Division Multiple Access), SC-FDMA (single carrier frequency division Multiple access), etc. It can be used for various wireless connection systems. CDMA can be implemented with a radio technology such as UTRA (Universal Terrestrial Radio Access) or CDMA2000. The TDMA can be implemented by a radio technology such as GSM (Global System for Mobile Communications) / GPRS (General Packet Radio Service) / EDGE (Enhanced Data Rates for GSM Evolution). OFDMA can be implemented by a wireless technology such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRA (Evolved UTRA), and the like. UTRA is a part of UMTS (Universal Mobile Telecommunication Systems). 3GPP (3rd Generation Partnership Project) LTE (Longterm Evolution) is part of E-UMTS (Evolved UMTS) that uses E-UTRA, adopts OFDMA in the downlink and SC-FDMA in the uplink To do. LTE-A (Advanced) is an advanced version of 3GPP LTE. In order to clarify the explanation, 3GPP LTE / LTE-A is mainly described, but the technical idea of the present invention is not limited thereto.

  In a wireless communication system, a terminal receives information from a base station via a downlink (Downlink, DL), and the terminal transmits information to the base station via an uplink (Uplink, UL). Information transmitted and received between the base station and the terminal includes data and various control information, and various physical channels exist depending on the type / use of information transmitted and received by these.

  FIG. 1 is a diagram for explaining a physical channel used in the 3GPP LTE system and a general signal transmission method using the physical channel.

  When the power is turned off or the terminal newly enters the cell, an initial cell search operation such as synchronization with the base station is performed in step S101. For this purpose, the terminal receives a primary synchronization channel (Primary Synchronization Channel, P-SCH) and a secondary synchronization channel (Secondary Synchronization Channel, S-SCH) from the base station, synchronizes with the base station, and receives a cell ID (cell identity). ) And other information. Thereafter, the terminal can receive the physical broadcast channel (PBCH) from the base station and acquire the in-cell broadcast information. Meanwhile, the UE can check a downlink channel state by receiving a downlink reference signal (DL RS) in an initial cell search stage.

  The terminal that has completed the initial cell search receives a physical downlink control channel (Physical Downlink Channel, PDCCH) and a physical downlink shared channel (Physical Downlink Control Channel, PDSCH) based on physical downlink control channel information in step S102. Specific system information can be acquired.

  Thereafter, the terminal may perform an arbitrary connection procedure (Random Access Procedure) such as steps S103 to S106 in order to complete the connection to the base station. For this purpose, the terminal transmits a preamble through a physical random access channel (PRACH) (S103), and passes through a physical downlink control channel and a corresponding physical downlink shared channel. Thus, a response message to the preamble can be received (S104). In case of contention based random access, contention resolution such as transmission of additional physical random access channel (S105) and reception of physical downlink control channel and corresponding physical downlink shared channel (S106) A process (Contention Resolution Procedure) can be performed.

  The terminal having performed the above-described process thereafter receives a physical downlink control channel / physical downlink shared channel (S107) and a physical uplink shared channel (Physical Uplink Shared Channel) as a general uplink / downlink signal transmission process. , PUSCH) / physical uplink control channel (Physical Uplink Channel, PUCCH) transmission (S108). The control information transmitted from the terminal to the base station is commonly referred to as uplink control information (UCI). UCI includes HARQ ACK / NACK (Hybrid Automatic Repeat and reQuest Acknowledgement / Negative-ACK), SR (Scheduling Request), CSI (Channel State Information), etc. CSI includes CQI (Channel Quality Indicator), PMI (Precoding Matrix Indicator), RI (Rank Indication), and the like. UCI is generally transmitted via PUCCH, but can be transmitted via PUSCH if control information and traffic data must be transmitted simultaneously. Also, the UCI can be transmitted aperiodically via the PUSCH according to the request / instruction of the network.

  FIG. 2 illustrates the structure of a radio frame. Uplink / downlink data packet transmission is performed in subframe units, and a subframe is defined as a time interval including a number of symbols. The 3GPP LTE standard supports a type 1 radio frame structure applicable to FDD (Frequency Division Duplex) and a type 2 radio frame structure applicable to TDD (Time Division Duplex).

  FIG. 2A illustrates the structure of a type 1 radio frame. The downlink radio frame is composed of 10 subframes, and one subframe is composed of 2 slots in the time domain. The time taken for one subframe to be transmitted is called TTI (transmission time interval). For example, the length of one subframe may be 1 ms, and the length of one slot may be 0.5 ms. One slot includes a plurality of OFDM symbols in the time domain, and includes a number of resource blocks (RBs) in the frequency domain. In the 3GPP LTE system, since OFDM is used in the downlink, an OFDM symbol indicates one symbol period. An OFDM symbol may also be referred to as an SC-FDMA symbol or symbol period. A resource block (RB) as a resource allocation unit may include a plurality of continuous subcarriers in one slot.

  The number of OFDM symbols included in the slot may vary depending on the configuration of CP (Cyclic Prefix). The CP includes an extended CP (extended CP) and a normal CP (normal CP). For example, when the OFDM symbol is configured by the normal CP, the number of OFDM symbols included in one slot may be seven. When an OFDM symbol is composed of an extended CP, the length of one OFDM symbol is increased, so that the number of OFDM symbols included in one slot is smaller than that of a normal CP. For example, in the case of the extended CP, the number of OFDM symbols included in one slot may be six. When the channel state is unstable, such as when the terminal moves at high speed, an extended CP can be used to further reduce interference between symbols.

  When normal CP is used, since the slot includes 7 OFDM symbols, the subframe includes 14 OFDM symbols. The first three OFDM symbols in the subframe can be allocated to PDCCH (Physical Downlink Control Channel), and the remaining OFDM symbols can be allocated to PDSCH (Physical Downlink Shared Channel).

  FIG. 2B illustrates the structure of a type 2 radio frame. A type 2 radio frame is composed of two half frames. The half frame includes 4 (5) general subframes and 1 (0) special subframes. The general subframe is used for uplink or downlink according to UL-DL configuration (Uplink-Downlink Configuration). A subframe is composed of two slots.

  Table 1 illustrates a subframe configuration in a radio frame according to the UL-DL configuration.

  In the table, D indicates a downlink subframe, U indicates an uplink subframe, and S indicates a special subframe. The special subframe includes DwPTS (Downlink Pilot TimeSlot), GP (Guard Period), and UpPTS (Uplink Pilot TimeSlot). DwPTS is used for initial cell search, synchronization or channel estimation at the terminal. UpPTS is used for channel estimation at the base station and uplink transmission synchronization of the terminal. The protection section is a section for removing interference generated in the uplink due to the multipath delay of the downlink signal between the uplink and the downlink.

  The structure of the radio frame is merely an example, and the number of subframes, the number of slots, and the number of symbols in the radio frame can be variously changed.

  FIG. 3 illustrates a resource grid of downlink slots.

  Referring to FIG. 3, the downlink slot includes a plurality of OFDM symbols in the time domain. Here, one downlink slot includes 7 OFDM symbols, and one resource block (RB) is illustrated as including 12 subcarriers in the frequency domain. However, the present invention is not limited to this. Each element on the resource grid is called a resource element (RE). One RB includes 12 × 7 RE. The number NDL of RBs included in the downlink slot depends on the downlink transmission band. The structure of the uplink slot may be the same as the structure of the downlink slot.

  FIG. 4 illustrates a downlink subframe structure.

  Referring to FIG. 4, a maximum of 3 (4) OFDM symbols positioned before the first slot in a subframe correspond to a control region to which a control channel is allocated. The remaining OFDM symbols correspond to a data area to which a PDSCH (physical downlink shared channel) is allocated, and the basic resource unit of the data area is RB. Examples of downlink control channels used in LTE include PCFICH (physical control format indicator channel), PDCCH (Physical Downlink Control Channel), and PHICH (physical hybrid ARQ index). PCFICH is transmitted in the first OFDM symbol of the subframe, and carries information on the number of OFDM symbols used for transmission of the control channel in the subframe. PHICH is a response to uplink transmission and carries a HARQ ACK / NACK (acknowledgement / negative-acknowledgement) signal. Control information transmitted through the PDCCH is called DCI (downlink control information). The DCI includes uplink or downlink scheduling information or an uplink transmission power control command for an arbitrary terminal group (Transmit Power Control Command).

  Control information transmitted via the PDCCH is called DCI (Downlink control information). As the DCI format (format), formats such as formats 0, 3, 3A, 4 for uplink and formats 1, 1A, 1B, 1C, 1D, 2, 2A, 2B, 2C, etc. are defined for downlink. The type of information field, the number of information fields, the number of bits of each information field, and the like vary depending on the DCI format. For example, the DCI format depends on the hopping flag (hopping flag), RB allocation (assignment), MCS (modulation coding scheme), RV (redundancy version), NDI (new data indicator), TPC (transHartQrtransQ process number). , Information such as PMI (precoding matrix indicator) confirmation is selectively included. Therefore, the size (size) of the control information that matches the DCI format changes depending on the DCI format. On the other hand, an arbitrary DCI format can be used for transmitting two or more types of control information. For example, DCI format 0 / 1A is used to carry DCI format 0 or DCI format 1, which are separated by a flag field.

  PDCCH is a DL-SCH (downlink shared channel) transmission format and resource allocation, UL-SCH (uplink shared channel) resource allocation information, PCH (paging channel) paging information, and DL-SCH system information (system information). , Resource allocation information of higher layer control messages such as random connection responses transmitted on PDSCH, transmission power control command for individual terminals within an arbitrary terminal group, activation of VoIP (voice over IP), etc. Transport. Multiple PDCCHs can be transmitted in the control region. The terminal can monitor a plurality of PDCCHs. The PDCCH is transmitted on one or a plurality of consecutive CCE (aggregate control channel element) aggregations. The CCE is a logical allocation unit used to provide a PDCCH having a predetermined coding rate according to a radio channel state. The CCE corresponds to a plurality of REGs (Resource Element groups). The PDCCH format and the number of available PDCCH bits are determined by the correlation between the number of CCEs and the coding rate provided by the CCEs. The base station determines the PDCCH format based on the DCI transmitted to the terminal, and adds a CRC (cyclic redundancy check) to the control information. The CRC is masked by a unique identifier (referred to as a radio network temporary identifier (RNTI)) depending on the owner or usage of the PDCCH. If the PDCCH is for a specific terminal, the unique identifier (for example, C-RNTI (cell-RNTI)) of the corresponding terminal is masked by the CRC. As another example, if the PDCCH is for a paging message, a paging indication identifier (eg, P-RNTI (paging-RNTI)) is masked to the CRC. If the PDCCH is related to system information (more specifically, SIB (system information block) described later), a system information identifier (for example, SI-RNTI (system information RNTI)) is masked by CRC. In order to indicate a random connection response, which is a response to the transmission of the random connection preamble of the terminal, RA-RNTI (Random Access-RNTI) is masked by the CRC.

  FIG. 5 illustrates an uplink subframe structure.

  Referring to FIG. 5, the subframe 500 includes two 0.5 ms slots 501. When the normal CP is used, each slot includes seven symbols 502, and one symbol corresponds to one SC-FDMA symbol. The resource block 503 is a resource allocation unit corresponding to 12 subcarriers in the frequency domain and one slot in the time domain. The structure of the uplink subframe is roughly divided into a data area 504 and a control area 505. The data area means a communication resource used for the terminal to transmit data such as voice and packet, and includes a PUSCH (Physical Up and Shared Channel). The control area means a communication resource used by the terminal to transmit uplink control information (Uplink Control Information, UCI), and includes PUCCH (Physical Uplink Channel).

  The PUCCH can be used to transmit the next uplink control information.

  -SR (Scheduling Request): information used to request an uplink UL-SCH resource. It is transmitted using an OOK (On-Off Keying) method.

  -HARQ-ACK: A response to a downlink data packet (eg, codeword) on the PDSCH. Indicates whether the downlink data packet has been successfully received. In response to a single downlink codeword, one HARQ-ACK bit is transmitted, and in response to two downlink codewords, two HARQ-ACK bits are transmitted. The HARQ-ACK response includes positive ACK (simply ACK), negative ACK (NACK), DTX, or NACK / DTX. Here, HARQ-ACK is mixed with HARQ ACK / NACK and ACK / NACK.

  -CSI (Channel State Information): Feedback information about the downlink channel. MIMO (Multiple Input Multiple Output) -related feedback information includes RI (Rank Indicator) and PMI (Precoding Matrix Indicator). 20 bits are used per subframe.

  The amount of control information that a terminal can transmit in a subframe depends on the number of SC-FDMAs available for transmission of control information. SC-FDMA that can be used for transmission of control information means the remaining SC-FDMA symbols excluding the SC-FDMA symbol for reference signal transmission in a subframe, and is a sub in which SRS (Sounding Reference Signal) is set. In the case of a frame, the last SC-FDMA symbol of the subframe is also excluded. The reference signal is used for coherent detection of PUCCH. PUCCH supports various formats depending on the information to be transmitted

  Table 2 shows the mapping relationship between the PUCCH format and UCI in LTE (-A).

  The SRS is transmitted over the last SC-FDMA symbol in the subframe (506). The SRS of many terminals transmitted via the same SC-FDMA symbol can be distinguished by frequency position / sequence. SRS is transmitted aperiodically or periodically.

  Hereinafter, TDD signal transmission timing in a single carrier (or cell) situation will be described with reference to FIGS.

  6 and 7 show PDSCH-UL ACK / NACK timing. Here, UL ACK / NACK is a response to DL data (eg, PDSCH), and means ACK / NACK transmitted in the uplink.

  Referring to FIG. 6, the UE may receive one or more PDSCH signals on M DL subframes (Subframe, SF) (S502_0 to S502_M-1). Each PDSCH signal is used to transmit one or a plurality (eg, two) of transmission blocks (TB) according to a transmission mode. Although not shown, a PDCCH signal instructing SPS release (Semi-Persistent Scheduling release) may be received in steps S502_0 to S502_M-1. If a PDSCH signal and / or an SPS-released PDCCH signal exist in M DL subframes, a terminal transmits a ACK / NACK (eg, ACK / NACK (payload) generation, ACK / NACK resource allocation, etc.) Then, ACK / NACK is transmitted through one UL subframe corresponding to M DL subframes (S504). ACK / NACK includes reception response information related to the PDSCH signal and / or the SPS release PDCCH signal in steps S502_0 to S502_M-1. The ACK / NACK is basically transmitted via the PUCCH, but if there is a PUSCH transmission at the time of ACK / NACK transmission, the ACK / NACK is transmitted via the PUSCH. The various PUCCH formats in Table 2 can be used for ACK / NACK transmission. Also, various methods such as ACK / NACK bundling and ACK / NACK channel selection can be used to reduce the number of ACK / NACK bits transmitted through the PUCCH format.

  As described above, in TDD, ACK / NACK for data received in M DL subframes is transmitted through one UL subframe (that is, M DL SF (s): 1 UL SF), and their relationship Is given by DASI (Downlink Association Set Index).

Table 3 shows DASI (K: {k ₀ , k ₁ ,..., K _M−1 }) defined in LTE (−A). Table 3 shows the interval between the DL subframe and the DL subframe associated with the ACK / NACK in terms of the UL subframe transmitting the ACK / NACK. Specifically, when there is a PDCCH instructing PDSCH transmission and / or SPS release (Semi-Persistent Scheduling release) in subframe nk (kεK), the terminal transmits ACK / NACK in subframe n

  FIG. 7 exemplifies UL ACK / NACK transmission timing when UL-DL configuration # 1 is set. In the figure, SFs # 0 to # 9 and SFs # 10 to # 19 respectively correspond to radio frames. In the figure, the numbers in the boxes indicate UL subframes associated with themselves in terms of DL subframes. For example, ACK / NACK for the SFSCH of PD # 5 is transmitted with SF # 5 + 7 (= SF # 12), and ACK / NACK for the PDSCH of SF # 6 is transmitted with SF # 6 + 6 (= SF # 12). Therefore, all ACK / NACKs for the downlink signals of SF # 5 / SF # 6 are transmitted by SF # 12. Similarly, ACK / NACK for the PDSCH of SF # 14 is transmitted with SF # 14 + 4 (= SF # 18).

  8 and 9 illustrate PHICH / UL grant (UG) -PUSCH timing. PUSCH can be transmitted corresponding to PDCCH (UL grant) and / or PHICH (NACK).

  Referring to FIG. 8, the terminal may receive PDCCH (UL grant) and / or PHICH (NACK) (S702). Here, NACK corresponds to an ACK / NACK response to the previous PUSCH transmission. In this case, the UE goes through a process for PUSCH transmission (eg, TB coding, TB-CW swapping, PUSCH resource allocation, etc.), and after k subframes, one or a plurality of transmission blocks (TB) via the PUSCH. ) Can be initialized / retransmitted (S704). This example assumes a normal HARQ operation in which the PUSCH is transmitted once. In this case, the PHICH / UL grant corresponding to the PUSCH transmission exists in the same subframe. However, in the case of subframe bundling in which PUSCH is transmitted a plurality of times through a plurality of subframes, PHICH / UL grants corresponding to PUSCH transmission can exist in different subframes.

  Table 4 shows UAI (Uplink Association Index) (k) for PUSCH transmission in LTE (-A). Table 4 shows the interval between the UL subframe associated with itself in the position of the DL subframe in which the PHICH / UL grant is detected. Specifically, when a PHICH / UL grant is detected in subframe n, the terminal can transmit the PUSCH in subframe n + k.

  FIG. 9 illustrates the PUSCH transmission timing when UL-DL configuration # 1 is set. In the figure, SFs # 0 to # 9 and SFs # 10 to # 19 respectively correspond to radio frames. In the figure, the numbers in the boxes indicate UL subframes associated with themselves in terms of DL subframes. For example, PUSCH for SF # 6 PHICH / UL grant is transmitted by SF # 6 + 6 (= SF # 12), and PUSCH for SF # 14 PHICH / UL grant is transmitted by SF # 14 + 4 (= SF # 18). .

  10 and 11 show PUSCH-PHICH / UL grant timing. PHICH is used to transmit DL ACK / NACK. Here, DL ACK / NACK is a response to UL data (eg, PUSCH), and means ACK / NACK transmitted in the downlink.

  Referring to FIG. 10, the terminal transmits a PUSCH signal to the base station (S902). Here, the PUSCH signal is used to transmit one or a plurality (for example, two) of transmission blocks (TB) according to a transmission mode. As a response to the PUSCH transmission, the BS performs ACK / NACK via PHICH after the k subframes through the process for transmitting ACK / NACK (eg, ACK / NACK generation, ACK / NACK resource allocation, etc.). It can be transmitted to the terminal (S904). The ACK / NACK includes reception response information related to the PUSCH signal in step S902. If the response to the PUSCH transmission is NACK, the base station can transmit the UL grant PDCCH for PUSCH retransmission to the terminal after k subframes (S904). This example assumes a normal HARQ operation in which the PUSCH is transmitted once. In this case, the PHICH / UL grant corresponding to the PUSCH transmission can be transmitted in the same subframe. However, in the case of subframe bundling, PHICH / UL grants corresponding to PUSCH transmission can be transmitted in different subframes.

  Table 5 shows LTE (-A) UAI (Uplink Association Index) (k) for PHICH / UL grant transmission. Table 6 shows the interval between itself and the associated UL subframe in the position of the DL subframe in which the PHICH / UL grant exists. Specifically, the PHICH / UL grant of subframe i corresponds to the PUSCH transmission of subframe i-k.

  FIG. 11 illustrates the PHICH / UL grant transmission timing when UL-DL configuration # 1 is set. In the figure, SFs # 0 to # 9 and SFs # 10 to # 19 respectively correspond to radio frames. In the figure, the numbers in the boxes indicate DL subframes associated with themselves from the viewpoint of UL subframes. For example, the PHICH / UL grant for SF # 2 PUSCH is transmitted by SF # 2 + 4 (= SF # 6), and the PHICH / UL grant for SF # 8 PUSCH is transmitted by SF # 8 + 6 (= SF # 14). Is done.

Next, PHICH resource allocation will be described. If there is PUSCH transmission in subframe #n, the terminal determines the corresponding PCHIH resource in subframe # (n + k _PHICH ). In FDD, k _PHICH has a fixed value (eg, 4). In TDD, k _PHICH has different values depending on the UL-DL configuration. Table 6 shows the k _PHICH value for TDD and is equivalent to Table 5.

  The PHICH resource is given by [PHICH group index, orthogonal sequence index]. The PHICH group index and the orthogonal sequence index are determined using (i) the smallest PRB index used for PUSCH transmission and (ii) the value of the 3-bit field for DMRS (DeModulation Reference Signal) cyclic shift. . (I) (ii) is indicated by the UL grant PDCCH.

  FIG. 12 illustrates the uplink-downlink frame timing relationship.

Referring to FIG. 12, transmission of an uplink radio frame i starts before (N _TA + N _TAoffset ) * T _s before the corresponding downlink radio frame. For LTE system, 0 = N _TA ≦ 20512, N _TAoffset = 0 in FDD, and N _TAoffset = 624 in TDD. The NT _aoffset value is a value that the base station and the terminal recognize in advance. If _NTA is indicated by a timing advance command in a random connection process, the UE adjusts the transmission timing of the UL signal (eg, PUCCH / PUSCH / SRS) according to the above equation. UL transmission timing is set to a multiple of 16T _s. The timing advance command instructs the change of the UL timing based on the current UL timing. Timing advance command in the random access response _{(T A)} is a 11-bit, _{T A} is 0,1,2, ..., indicate the value of 1282, the timing adjustment value _{(N TA)} is _N TA _{= T} A * Is given as 16. Otherwise, the timing advance instruction (T _A ) is 6 bits, T _A indicates a value of 0, 1, 2,..., 63, and the timing adjustment value (N _TA ) is N _{TA, new} = N _TA, given as _{old + (T A -31) *} 16. The timing advance command received at SF # n is applied from SF # n + 6. In the case of FDD, as shown in the figure, the transmission time point of UL SF # n is raised with reference to the start time point of DL SF # n. On the other hand, in the case of TDD, the transmission time point of UL SF # n is raised based on the end time point of DL SF # n + 1 (not shown).

Example: short DL / UL

  In the next system after LTE-A, control and data transmission based on low latency can be considered. For this purpose, a time unit (for example, Transmission Time Unit, TTI) for transmitting / receiving a single DL / UL data (for example, DL / UL-SCH transport block) is an existing single SF (that is, 1 ms). ) It may have to be smaller. For example, for control and data transmission based on low delay, the TTI may have to be composed of 3 OFDMA / SC-FDMA symbols or 1 slot interval. For convenience, terms are defined as follows:

  -Short TU: indicates a time unit (i.e., TTI) in which single DL / UL data (e.g., transmission block) is transmitted and received. For low delay transmission, the short TU is set smaller than the TTI (ie, 1SF = 1 ms) of the existing system (eg, LTE / LTE-A). For example, the short TU can be set to three OFDMA / SC-FDMA symbols or one slot period. For convenience, the TTI of the existing system is referred to as a normal TTI and the short TU is referred to as a short TTI.

  -Short DL: Indicates a DL section composed of one short TU.

  -Short UL: Indicates a UL section composed of one short TU.

  -Short TI: (minimum) time interval / latency between control information and data (see FIGS. 6 to 11). As an example, the short TI includes (i) (minimum) time interval / latency (see FIG. 6) between DL data reception time via the short DL and HARQ-ACK transmission time via the short UL (see FIG. 6), (ii) short DL The (minimum) time interval / latency between the UL grant reception time via the UL and the UL data transmission time via the short UL can be shown (see FIG. 8). The short TI can be indicated by a time interval between the short DL / UL and the short UL / DL. For low-delay transmission, the short TI can be set smaller than the time interval (eg, 4SFs = 4 ms) of the existing system (eg, LTE / LTE-A). As an example, the short TI can be set to one or two SF periods (eg, 1 ms or 2 ms).

  On the other hand, in the existing TDD system (for example, LTE / LTE-A), SF of 1 ms unit is configured based on the UL-DL configuration (see Table 1) broadcasted via SIB. In order to configure a short TU in an existing TDD system, there can be a method in which a short DL is inserted only in a DL SF and a short UL is inserted only in a UL SF. However, in this method, since the short DL / UL is configured only depending on the SF structure based on the UL-DL configuration, between the control information and data (that is, a plurality of continuous SFs (DL or UL)) (that is, It may not be easy to support (secure and maintain) the short TI between the short DL / UL and the short UL / DL. As an example, in the case of TDD UL-DL configuration # 1, the SF configuration is set to [DSUUDDSUUD] in units of radio frames. However, if the above method is applied, each of the DL SF and UL SF continues at least twice. Therefore, it may be difficult to ensure a short TI of less than 2 ms (eg, 1 ms). Here, D, S, and U mean DL SF, S (special) SF, and UL SF, respectively (see Table 1).

  Hereinafter, the present invention proposes a short TU configuration method for low delay based control and data transmission in a TDD system. More specifically, a short DL and short UL configuration method for supporting a short TI between control information and data in an existing TDD system based on UL / DL SF configuration is presented. On the other hand, in the case of UL data corresponding to the UL grant DCI / PHICH detected via the short DL or the HARQ-ACK for the DL data received via the short DL, the short DL after the short TI (or constant from now on) It can be sent via the short UL). In the case of the DL grant DCI corresponding to the DL data corresponding to the HARQ-ACK (for example, NACK) transmitted via the short UL (retransmission) or the PHICH / UL grant DCI corresponding to the UL data transmitted via the short UL , From the corresponding short UL through the short DL after the short TI (or within a fixed time from now on).

  On the other hand, the following description exemplifies a case where a short UL / DL is configured in an existing SF, but the SF is only an example of a time interval that can include a plurality of short TUs. Therefore, in the following, the SF can be generalized as an arbitrary time interval including a plurality of short TUs (for example, a slot, a radio frame, a DL interval, a UL interval, etc.).

  (1) Method of configuring short DL in UL SF (Method 1)

  One or a plurality of short DLs can be configured in one existing UL SF. Specifically, Opt 1) A plurality of short DLs are configured over one UL SF on the time axis, or Opt 2) One over a section excluding some symbols in the UL SF (first and / or last). The above short DL can be configured. The symbol includes an OFDAM symbol or an SC-FDMA symbol. In the case of a symbol period excluded from Opt 2, Alt 1) used / set as a gap for switching between DL / UL, Alt 2) set to original UL SF or set separately to short TU operating terminal A specific UL signal (for example, SRS) transmitted can be transmitted. The method can be similarly applied when one or a plurality of short ULs are configured in one UL SF.

  Meanwhile, a short DL may be configured or configurable UL SF information may be set in the terminal, and the terminal may perform DL signal / channel detection and reception operation on the short DL with a corresponding UL SF in a specific situation (for example, DL / UL grant DCI detection that schedules short DL / UL, DL data reception scheduled in short DL, and the like). As an example, if there is no scheduling / configuration for a UL signal / channel in a specific UL SF (and / or a UL SF adjacent to the UL SF immediately after the UL SF), the terminal may perform DL (for example, short DL with respect to the short DL). , DL / UL grant DCI, etc.) detection / reception may be attempted. As another example, when HARQ-ACK or UL data transmission is performed via a specific short UL, the terminal transmits the short DL to the short DL at a time point after the short TI (or within a certain period of time) from the corresponding short UL. In contrast, DL (eg, DL / UL grant DCI, PHICH, etc. that schedules DL / UL data (re) transmission) detection / reception may be attempted.

  (2) Method of configuring short UL in DL SF (Method 2)

  One or a plurality of short ULs can be configured in one existing DL SF. Specifically, with the DL SF set to (fake) MBSFN (Multicast Broadcast Single Frequency Network) SF, the first partial symbol (or the first partial symbol and the last partial symbol) in the corresponding DL SF is set. One or more short ULs can be formed in the remaining sections. The MBSFN SF is divided into a non-MBSFN area and an MBSFN area. The non-MBSFN area is composed of MBSFN SF and first to two OFDMA symbols, and the MBSFN area is composed of MBSFN SF and OFDMA symbols not used for the non-MBSFN area. Since the existing terminal reads only the non-MBSFN area in the MBFSN SF, it is possible to prevent the existing terminal from being affected by configuring the short UL in the MBSFN area. That is, a specific DL SF can be set in the MBSFN SF for the purpose of configuring a short UL that is not an MBSFN service (fake MBSFN SF). MBSFN SF is indicated using a bitmap and is repeated periodically. The first partial symbols that are removed in the short SF configuration in the DL SF are control transmissions (for example, PDCCH, PHICH, etc.) and DL / for terminals that operate only in the existing TTI (and / or terminals that are configured with the short TU operation). Can be used / set for UL switching gap applications. On the other hand, Alt 1/2 of Method 1 can be applied to the last partial symbol that is removed in the configuration of the short UL in the DL SF. The method can be similarly applied when one or a plurality of short DLs are configured in one DL SF.

  Meanwhile, DL SF information (configured in MBSFN SF) that can be configured or configured as a short UL can be set in the terminal, and the terminal can perform UL in a specific situation via the short UL in the corresponding DL SF. Signal / channel transmission operations (eg, HARQ-ACK transmission for DL data reception in the short DL, UL data transmission scheduled from the short DL, etc.) can be performed. As an example, when DL data or UL grant DCI (and / or PHICH) is received via a specific short DL, the terminal is set with MBSFN after the short TI (or within a certain period of time) from the corresponding short DL. UL (for example, HARQ-ACK for DL data reception, UL data corresponding to UL grant DCI / PHICH, etc.) can be transmitted via a short UL in the DL SF.

  (3) Method of configuring short DL in S SF (Method 3)

  One or a plurality of short DLs can be configured in one existing SSF. Specifically, one or more short DLs may be configured in the remaining section excluding some symbols in the S SF (first and / or last). The first partial symbols that are removed when configuring short DL in S SF are used / configured for control transmission (eg, PDCCH, PHICH, etc.) for existing TTI operating terminals (and / or short TU operating terminals). Can do. On the other hand, Alt 1/2 of Method 1 can be applied to the last partial symbol that is removed in the configuration of short DL in S SF. In the case of a specific short DL, all or a part of the symbols constituting the short DL may be outside the DwPTS interval set in the original SSF or overlap the UpPTS interval.

  S SF information in which the short DL is configured or configurable can be set in the terminal, and the terminal can perform DL signal / channel detection and reception operation on the short DL in the corresponding S SF (for example, short DL / DL / UL grant DCI detection for scheduling UL, reception of DL data scheduled for short DL, etc.) can be performed. As an example, if there is no scheduling / setting for a UL signal / channel in a specific S SF (and / or a UL SF adjacent immediately after the corresponding SF), the terminal performs DL (for example, DL / UL grant DCI, etc.) detection / reception may be attempted. As another example, when HARQ-ACK or UL data transmission is performed through a specific short UL, the terminal transmits the short DL to the short DL at a time point after the short TI (or within a certain period of time) from the corresponding short UL. In contrast, DL (eg, DL / UL grant DCI, PHICH, etc. that schedules DL / UL data (re) transmission) can be detected / received.

  (4) Method of configuring short UL in S SF (Method 4)

  One or a plurality of short ULs can be configured in one existing SSF. Specifically, one or more short ULs may be configured in the remaining section excluding the first partial symbol (or the first partial symbol and the last partial symbol) in the S SF. The first partial symbols that are removed when configuring short UL in S SF are the transmission of control information (eg, PDCCH, PHICH, etc.) and DL / UL switching gap for existing TTI operating terminals (and / or short TU operating terminals). It can be used / set for the application. On the other hand, Alt 1/2 of Method 1 can be applied to the last partial symbol that is removed in the configuration of short UL in S SF. Also, because of the configuration of the short UL in the S SF, the S SF configuration can preferably be set to the one with the smallest DwPTS interval (eg, 3 symbol intervals). In addition, in the case of a specific short UL, all or a part of the symbols constituting the short UL may be outside the UpPTS interval set in the original SSF or overlap with the DwPTS interval.

  Table 7 shows the length of DwPTS / GP / UpPTS according to the SSF configuration. In S SF configurations # 0 and # 5, DwPTS is composed of three symbols, and in other S SF configurations, DwPTS is composed of more than three symbols.

  On the other hand, S SF information in which a short UL is configured or configurable can be set in the terminal, and the terminal performs a UL signal / channel transmission operation (for example, via a short UL in the S SF corresponding to a specific situation) HARQ-ACK transmission in response to DL data reception in the short DL, UL data transmission scheduled from the short DL, and the like. As an example, when DL data or UL grant DCI (and / or PHICH) is received via a specific short DL, the terminal receives the short DL in the S SF after the short TI (or within a certain period of time) from the corresponding short DL. UL (eg, HARQ-ACK for DL data reception, UL data corresponding to UL grant DCI / PHICH, etc.) can be transmitted via the UL.

  FIG. 13 illustrates a short UL / DL configuration according to one embodiment of the present invention. FIG. 13 exemplifies a case where the short DL / UL configuration method is applied to a TDD system having an SF configuration based on the UL-DL configuration # 1. In the drawing, it is assumed that four short TU intervals are the same as one SF interval (for example, 0.25 ms), and short TI is 1 ms (or one SF or four short TU intervals). did. As can be seen from the drawing, the short DL configuration method based on Method 3 is used for S of SF # 1, and the short DL configuration method based on Method 1 is used for U of SF # 3. A short UL configuration scheme based on Method 2 can be applied to Method 2 and a short UL configuration scheme based on Method 4 can be applied to S of SF # 6. For the sake of explanation, the drawing shows the case where Methods 1 to 4 are all combined. However, this is by way of example only, Methods 1-4 can be used alone or in any combination. Also, in the drawing, {d0, u0, d2, u2, d4, u4, d6, u6, d8} on the short TU number are considered as one short DL / UL aggregation corresponding to the short TI interval, and {d1, u1, d3, u3, d5, u5, d7, u7, d9} can be considered as another short DL / UL aggregation corresponding to the short TI interval. In the drawing, changeable / unchangeable indicates whether or not a short UL configuration is possible.

  Meanwhile, the short DL / UL of the present invention can be configured over the entire system BW (bandwidth) or only in a specific frequency (for example, RB) region smaller than the system BW.

  FIG. 14 illustrates a signal processing process according to an embodiment of the present invention.

  Referring to FIG. 14, the terminal may receive system information indicating a TDD UL-DL configuration (S1402). The TDD UL-DL configuration indicates the SF configuration of a radio frame (see Table 1). When a plurality of cells are aggregated to a terminal based on CA (Carrier Aggregation), a TDD UL-DL configuration may be indicated for each cell. Thereafter, the terminal may check the TTI configuration of SF # n (S1404), and the TTI configuration of SF # n may be a normal TTI or a short TTI. The normal TTI is a TTI of an existing system (for example, LTE / LTE-A), and has a length of one SF section (that is, 1 ms). On the other hand, the short TTI is set to be smaller than the TTI of the existing system (for example, LTE / LTE-A). For example, the TU is set to 3 OFDMA / SC-FDMA symbols or one slot period (that is, 0.5 ms). Can be done. When the TTI configuration of SF # n is normal TTI, the terminal can perform a signal processing process under the assumption that SF # n is configured with one TTI (S1406a). In this case, transmission / reception of DL / UL data can be performed in SF units. On the other hand, if the TTI configuration of SF # n is short TTI, the terminal can perform a signal processing process under the assumption that SF # n is configured with multi-TTI (S1406b). Here, the signal processing process includes a signal processing process for transmitting and receiving signals through various physical channels of FIG. For example, (i) a signal processing process for receiving DL grant and receiving corresponding DL data, (ii) a signal processing process for receiving DL data and transmitting HARQ-ACK for the DL data, (iii) ) Including signal processing for receiving UL grant / PHICH and transmitting UL data for it. Here, transmission / reception of DL / UL data can be performed in units smaller than SF. In SF # n, the configuration of the short TTI and the signaling scheme related thereto can follow the methods 1 to 4. For example, the structure of the short TTI in SF # n can be configured as shown in FIG.

  (5) Inter-cell interference control scheme with short DL / UL configuration

  When the short DL / UL is configured in the UL / DL SF set in the existing TDD system, it may be preferable to consider the influence of interference on or from the adjacent cell. As an example, if short DL / UL setting availability and related information are not exchanged / shared between adjacent cells, or if the short DL / UL configuration pattern is not shared tightly in real time, short DL / UL and (short DL) Interference between general UL / DL SFs (/ UL not configured) can result in significant performance degradation for the entire system.

  For this purpose, whether or not the short DL / UL can be set and the (candidate) SF (and / or short DL / UL configurable (candidate) frequency (for example, RB) region) information that can be configured in the short DL / UL cell Can be exchanged by signaling in between. In addition, a short UL that is independent of a general UL SF (Power Control) process may be performed for a short UL that is entirely or specific (for example, configured in a DL (or S) SF). In addition, UL TA (timing advance) can be set / controlled independently only for the corresponding short UL. Specifically, open loop PC parameters (eg, PO_PUSCH, alpha, PO_PUCCH related parameters, etc.) applied to PUSCH and PUCCH transmission in short UL (independent of general UL SF) may be set independently. it can. In addition, TPC commands can also be accumulated independently only for short UL (separated from general UL SF). Also, the UL PC process (for example, open-loop PC parameter setting, TPC command application, etc.) is performed in common for short UL and general UL SF, and a specific power offset is added to the UL transmission power in short UL / A method of applying is also possible.

  In addition, a specific UL (or S) SF (for example, which can include a short DL) is also performed by an independent UL PC process which is separate from other (for example, which does not include a short DL) UL SF. Can be Also, independent open-loop PC parameter setting and TPC command accumulation operations can be performed for UL transmission in the specific UL (or S) SF (separately from other general UL SF). Also, the UL PC process is performed in common for all UL SFs, and a specific power offset can be added / applied to the UL transmission power in the specific UL (or S) SF.

  The application of the proposed method of the present invention is not limited only to a TDD system, and it is also general when a short UL is configured / set in an arbitrary DL SF and / or a short DL is configured / set in an arbitrary UL SF. It can be extended in general. As an example, a short UL is configured / configured in a specific DL SF on a DL carrier and / or a short DL is configured / configured in a specific UL SF on a UL carrier by applying the proposed method in the environment of an FDD system. The plan to set can be considered.

  FIG. 15 illustrates a base station, a relay and a terminal applicable to the present invention.

  Referring to FIG. 150, the wireless communication system includes a base station (BS) 110 and a terminal (UE) 120. If the wireless communication system includes a relay, the base station or terminal can be replaced with a relay.

  The base station 110 includes a processor 112, a memory 114, and a radio frequency (RF) unit 116. The processor 112 may be configured to implement the processes and / or methods proposed in the present invention. The memory 114 is connected to the processor 112 and stores various information related to the operation of the processor 112. The RF unit 116 is connected to the processor 112 and transmits and / or receives radio signals. The terminal 120 includes a processor 122, a memory 124, and an RF unit 126. The processor 122 may be configured to implement the processes and / or methods proposed in the present invention. The memory 124 is connected to the processor 122 and stores various information related to the operation of the processor 122. The RF unit 126 is connected to the processor 122 and transmits and / or receives a radio signal.

  In each of the embodiments described above, the constituent elements and features of the present invention are combined in a predetermined form. Each component or feature should be considered optional unless stated otherwise. Each component or feature can be implemented in a form that is not combined with other components or features. In addition, it is possible to configure an embodiment of the present invention by combining some components and / or features. The order of operations described in the embodiments of the present invention can be changed. Some configurations or features of one embodiment may be included in other embodiments, or may be replaced with configurations or features corresponding to other embodiments. It is obvious that claims which are not explicitly cited in the claims can be combined to constitute an embodiment, or can be included as new claims by amendment after application.

  In this document, each embodiment of the present invention has been described mainly with respect to a data transmission / reception relationship between a terminal and a base station. The specific operation described as being performed by the base station in this document may be performed by its upper node in some cases. That is, it is obvious that various operations performed for communication with a terminal in a network including a plurality of network nodes including a base station can be performed by a network node other than the base station or the base station. The base station may be replaced with terms such as a fixed station, Node B, eNode B (eNB), access point, and the like. The terminal can be replaced with terms such as UE (User Equipment), MS (Mobile Station), and MSS (Mobile Subscriber Station).

  Embodiments according to the present invention can be implemented by various means such as hardware, firmware, software, or a combination thereof. In the case of implementation by hardware, one embodiment of the present invention includes one or more ASICs (application specific integrated circuits), DSPs (digital signal processing), DSPDs (digital signal processing), DSPS (digital signal processing), DSPs (digital signal processing), DSPS (digital signal processing). , FPGAs (Field Programmable Gate Arrays), processors, controllers, microcontrollers, microprocessors, and the like.

  In the case of implementation by firmware or software, an embodiment of the present invention may be implemented in the form of modules, processes, functions, etc. that perform the functions or operations described above. The software code is stored in the memory unit and can be driven by the processor. The memory unit is located inside or outside the processor, and can exchange data with the processor by various means already announced.

  It will be apparent to those skilled in the art that the present invention can be embodied in other specific forms without departing from the characteristics of the present invention. Accordingly, the above detailed description should not be construed as limiting in all aspects, but should be considered as exemplary. The scope of the invention should be determined by reasonable interpretation of the appended claims, and all changes that come within the equivalent scope of the invention are included in the scope of the invention.

    The present invention can be used for a terminal, a base station, or other equipment of a wireless mobile communication system. Specifically, the present invention is applicable to a method for transmitting uplink control information and an apparatus therefor.

Claims (10)

A method in which a terminal performs signal processing in a wireless communication system,
Receiving system information indicating a TDD UL-DL configuration;
Receiving MBSFN SF allocation information;
Performing a signal processing process for the SF # n based on a TTI configuration of the SF # n,
The SF # n is configured with a single TTI when the SF # n is a non-MBSFN SF, and the SF # n is configured with multi-TTI when the SF # n is an MBSFN SF.   The method of claim 1, wherein if the SF # n is an MBSFN SF, the SF # n includes one or more DL sections and one or more UL sections corresponding to the multi-TTI.   The method according to claim 1, wherein if the SF # n is an MBSFN SF, the SF # n includes a plurality of DL sections corresponding to the multi-TTI.   The TTI is configured with 14 OFDMA symbols when the SF # n is a non-MBSFN SF, and the TTI is configured with 3 OFDMA symbols when the SF # n is an MBSFN SF. Method.   The TTI is configured with two 0.5 ms slots when the SF # n is a non-MBSFN SF, and the TTI is configured with one 0.5 ms slot when the SF # n is an MBSFN SF. The method according to 1. A terminal used in a wireless communication system,
An RF unit;
A processor, the processor comprising:
Receiving system information indicating the TDD UL-DL configuration;
MBSFN SF allocation information is received,
Based on the TTI configuration of SF # n, configured to perform a signal processing process for the SF # n,
If the SF # n is a non-MBSFN SF, the SF # n is configured with a single TTI, and if the SF # n is an MBSFN SF, the SF # n is configured with a multi-TTI.   The terminal according to claim 6, wherein if the SF # n is an MBSFN SF, the SF # n includes one or more DL sections and one or more UL sections corresponding to the multi-TTI.   The terminal according to claim 6, wherein when the SF # n is an MBSFN SF, the SF # n includes a plurality of DL sections corresponding to the multi-TTI.   The TTI is configured with 14 OFDMA symbols when the SF # n is a non-MBSFN SF, and the TTI is configured with 3 OFDMA symbols when the SF # n is an MBSFN SF. Terminal.   The TTI is configured with two 0.5 ms slots when the SF # n is a non-MBSFN SF, and the TTI is configured with one 0.5 ms slot when the SF # n is an MBSFN SF. 6. The terminal according to 6.